NASA announced last month that it plans to make oxygen from carbon dioxide as part of a larger $2 billion project.
Of course, NASA isn’t making oxygen. It just wants to drive chemical reactions that combine the single, separate… oxygen atoms in molecules of carbon dioxide into molecules of free oxygen.
Every green plant and alga on Earth has done the same thing with water molecules since the dawn of life. Indeed, they have done this long enough — more than 3 billion years — that our atmosphere has accumulated enough free oxygen to support life as we know it today.
If green plants and algae have done this for so long, then why is NASA spending so much money to generate more free oxygen? The answer, of course, is location, location, location.
NASA needs free oxygen on Mars.
If NASA scientists knew they had a ready supply of liquid water, carbon dioxide and sunlight on Mars, they could just send up some plant seeds and produce all the free oxygen they need, as well as food for astronauts.
What water exists there, however, is frozen and generally below the Martian surface.
NASA’s efforts to generate free oxygen permit us to reflect on the feat plants and algae have quietly performed on Earth for billions of years. Using sunlight, plants build sugar molecules by attaching parts of water molecules to modified carbon-dioxide molecules.
The free oxygen molecules that plants release in the process come from what’s left of those broken water molecules.
Think about that. Plants break apart water molecules and attach part of them to carbon-dioxide molecules to make sugar. Don’t try that at home, at least not without green plants and sunlight.
Water and carbon dioxide are two of the most non-reactive compounds in nature. They don’t burn. In fact, we use them to stop things from burning.
Most household fires consume things derived from plants and the sugars they made from water and carbon dioxide using sunlight energy. Think of a burning marshmallow or steak on a grill. They release the sunlight energy, water and carbon dioxide that plants used in making the sugars from which they formed.
The sugars and the structures that plants make out of them can become buried and fossilized. Since the start of the Industrial Revolution, we have mined those fossilized plants and algae in the form of coal, oil and natural gas.
We burn them to release their sunlight energy in our car engines and other machines. We also release the carbon dioxide that plants formed hundreds of millions of years ago.
Over the past 200 years, we have burned a vast reserve of accumulated fossilized fuels derived from plants and algae and have released historically unprecedented levels of atmospheric carbon dioxide. That greenhouse gas likely contributes to ongoing climate changes and warming.
It makes sense for NASA to go boldly to Mars and make oxygen from carbon dioxide. Some people might want to move there at the rate we’re releasing atmospheric carbon dioxide on Earth.
View original article at: Biology | NASA wants to create oxygen from CO2 on Mars